Tongtong Liu , Da Li , Yan Tian , Jiajie Zhou , Ye Qiu , Dongyi Li , Guohong Liu , Yujie Feng
{"title":"提高人工湿地的脱氮能力：综合垂直流系统中进水基质浓度的作用","authors":"Tongtong Liu , Da Li , Yan Tian , Jiajie Zhou , Ye Qiu , Dongyi Li , Guohong Liu , Yujie Feng","doi":"10.1016/j.ese.2024.100411","DOIUrl":null,"url":null,"abstract":"<div><p>Recent advancements in constructed wetlands (CWs) have highlighted the imperative of enhancing nitrogen (N) removal efficiency. However, the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms. Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands (IVFCWs), using wastewaters enriched with NO<sub>3</sub><sup>−</sup>-N and NH<sub>4</sub><sup>+</sup>-N at varying carbon to nitrogen (C/N) ratios (1, 3, and 6). In the NO<sub>3</sub><sup>−</sup>-N enriched systems, a positive correlation was observed between the C/N ratio and total nitrogen (TN) removal efficiency, which markedly increased from 13.46 ± 2.23% to 87.00 ± 2.37% as the C/N ratio escalated from 1 to 6. Conversely, in NH<sub>4</sub><sup>+</sup>-N enriched systems, TN removal efficiencies in the A-6 setup (33.69 ± 4.83%) were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems, attributed to constraints in dissolved oxygen (DO) levels and alkalinity. Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification, microbial N assimilation, and dissimilatory nitrate reduction to ammonium (DNRA) predominated in NO<sub>3</sub><sup>−</sup>-N systems with higher C/N ratios (C/N ≥ 3). In contrast, aerobic denitrification and microbial N assimilation were the primary pathways in NH<sub>4</sub><sup>+</sup>-N systems and low C/N NO<sub>3</sub><sup>−</sup>-N systems. A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12–47.12% and 8.51–38.96% in NO<sub>3</sub><sup>−</sup>-N systems, respectively, and 0.55–17.35% and 7.83–33.55% in NH<sub>4</sub><sup>+</sup>-N systems to TN removal. To enhance N removal, strategies for NO<sub>3</sub><sup>−</sup>-N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes, while NH<sub>4</sub><sup>+</sup>-N dominated systems require optimization of carbon utilization pathways, and ensuring adequate DO and alkalinity supply.</p></div>","PeriodicalId":34434,"journal":{"name":"Environmental Science and Ecotechnology","volume":null,"pages":null},"PeriodicalIF":14.0000,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666498424000255/pdfft?md5=2f1e9b9a567b5a15c78ccb35312d8faa&pid=1-s2.0-S2666498424000255-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems\",\"authors\":\"Tongtong Liu , Da Li , Yan Tian , Jiajie Zhou , Ye Qiu , Dongyi Li , Guohong Liu , Yujie Feng\",\"doi\":\"10.1016/j.ese.2024.100411\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Recent advancements in constructed wetlands (CWs) have highlighted the imperative of enhancing nitrogen (N) removal efficiency. However, the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms. Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands (IVFCWs), using wastewaters enriched with NO<sub>3</sub><sup>−</sup>-N and NH<sub>4</sub><sup>+</sup>-N at varying carbon to nitrogen (C/N) ratios (1, 3, and 6). In the NO<sub>3</sub><sup>−</sup>-N enriched systems, a positive correlation was observed between the C/N ratio and total nitrogen (TN) removal efficiency, which markedly increased from 13.46 ± 2.23% to 87.00 ± 2.37% as the C/N ratio escalated from 1 to 6. Conversely, in NH<sub>4</sub><sup>+</sup>-N enriched systems, TN removal efficiencies in the A-6 setup (33.69 ± 4.83%) were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems, attributed to constraints in dissolved oxygen (DO) levels and alkalinity. Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification, microbial N assimilation, and dissimilatory nitrate reduction to ammonium (DNRA) predominated in NO<sub>3</sub><sup>−</sup>-N systems with higher C/N ratios (C/N ≥ 3). In contrast, aerobic denitrification and microbial N assimilation were the primary pathways in NH<sub>4</sub><sup>+</sup>-N systems and low C/N NO<sub>3</sub><sup>−</sup>-N systems. A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12–47.12% and 8.51–38.96% in NO<sub>3</sub><sup>−</sup>-N systems, respectively, and 0.55–17.35% and 7.83–33.55% in NH<sub>4</sub><sup>+</sup>-N systems to TN removal. To enhance N removal, strategies for NO<sub>3</sub><sup>−</sup>-N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes, while NH<sub>4</sub><sup>+</sup>-N dominated systems require optimization of carbon utilization pathways, and ensuring adequate DO and alkalinity supply.</p></div>\",\"PeriodicalId\":34434,\"journal\":{\"name\":\"Environmental Science and Ecotechnology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":14.0000,\"publicationDate\":\"2024-03-20\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S2666498424000255/pdfft?md5=2f1e9b9a567b5a15c78ccb35312d8faa&pid=1-s2.0-S2666498424000255-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Environmental Science and Ecotechnology\",\"FirstCategoryId\":\"93\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666498424000255\",\"RegionNum\":1,\"RegionCategory\":\"环境科学与生态学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"ENVIRONMENTAL SCIENCES\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Environmental Science and Ecotechnology","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666498424000255","RegionNum":1,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENVIRONMENTAL SCIENCES","Score":null,"Total":0}
Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems
Recent advancements in constructed wetlands (CWs) have highlighted the imperative of enhancing nitrogen (N) removal efficiency. However, the variability in influent substrate concentrations presents a challenge in optimizing N removal strategies due to its impact on removal efficiency and mechanisms. Here we show the interplay between influent substrate concentration and N removal processes within integrated vertical-flow constructed wetlands (IVFCWs), using wastewaters enriched with NO3−-N and NH4+-N at varying carbon to nitrogen (C/N) ratios (1, 3, and 6). In the NO3−-N enriched systems, a positive correlation was observed between the C/N ratio and total nitrogen (TN) removal efficiency, which markedly increased from 13.46 ± 2.23% to 87.00 ± 2.37% as the C/N ratio escalated from 1 to 6. Conversely, in NH4+-N enriched systems, TN removal efficiencies in the A-6 setup (33.69 ± 4.83%) were marginally 1.25 to 1.29 times higher than those in A-3 and A-1 systems, attributed to constraints in dissolved oxygen (DO) levels and alkalinity. Microbial community analysis and metabolic pathway assessment revealed that anaerobic denitrification, microbial N assimilation, and dissimilatory nitrate reduction to ammonium (DNRA) predominated in NO3−-N systems with higher C/N ratios (C/N ≥ 3). In contrast, aerobic denitrification and microbial N assimilation were the primary pathways in NH4+-N systems and low C/N NO3−-N systems. A mass balance approach indicated denitrification and microbial N assimilation contributed 4.12–47.12% and 8.51–38.96% in NO3−-N systems, respectively, and 0.55–17.35% and 7.83–33.55% in NH4+-N systems to TN removal. To enhance N removal, strategies for NO3−-N dominated systems should address carbon source limitations and electron competition between denitrification and DNRA processes, while NH4+-N dominated systems require optimization of carbon utilization pathways, and ensuring adequate DO and alkalinity supply.
期刊介绍：
Environmental Science & Ecotechnology (ESE) is an international, open-access journal publishing original research in environmental science, engineering, ecotechnology, and related fields. Authors publishing in ESE can immediately, permanently, and freely share their work. They have license options and retain copyright. Published by Elsevier, ESE is co-organized by the Chinese Society for Environmental Sciences, Harbin Institute of Technology, and the Chinese Research Academy of Environmental Sciences, under the supervision of the China Association for Science and Technology.
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